Means for deflating pneumatic tubes



Feb. 20, 1934. w. V, SMlTH 1,947,678

MEANS FOR DEFLATING PNEUMATIC TUBES Filed March 7, 1930 www@ g 2]' 5 INVENTOR.

Patented Feb. 20, 1934 UNITED STATES .Y g Y 1,947,678

PATE-NT oFFlcE y TUB Walter V. Smith, South Hadley Falls, Mass., as-

signor to The Fisk Rubber Company, Chicopee Falls, Mass.,

a corporation of Massachusetts Application March 7, 1930. Serial No. 434,093

1 Claim.

My invention relates to apparatus for deflating pneumatic tubes such, for example, as the inner tubes used in pneumatic tires which are provided with valves normally holding the air in the tubes.

At certain stages during the manufacture of such tubes as, for example, during inspection it is customary to innate, or partially inflate, the tubes and it is then necessary to later deflate the tubes for the purpose of Wrapping and packaging or for other operations. Various devices are now in use for rapidly withdrawing the air from the tubes but such devices are relatively complicated. It is the object of my invention to provide apparatus by which the tubes may be deflated in an expeditious manner and at a saving in cost and to provide a device for carrying out the invention which shall be simple in construction and eITicient in operation.

In the accompanying drawing which illustrates one embodiment of my structure,

Fig. 1 is a plan view showing a tube in deflating position;

Fig. 2 is a side elevation taken substantially along lines 2-2 of Fig. l, being partly in section and on an enlarged scale, showing one of the deflating heads;

Fig. 3 is a section on line 3 3 o-f Fig. the Valve in deiating position;

Fig. 4 is a similar View showing the valve in venting position;

Fig. 5 is a detail view, partly in section, showing a deating cap in position on the end of the Valve stem; and

Fig. 6 is a section on line 6 6 of Fig. 1.

According to my invention at the end of the inspection or testing operation I apply to the end of the valve stem a deating cap having resilient side walls such, for example, as the cap disclosed and claimed in Patent No. 1,876,715 issued September 13, 1932 on an application by Charles Edgar Maynard, which cap is shown in the accompanying drawing for purpose of illustration.

The deilating cap, generally indicated at 10, is held to the valve stem 1l of the tube 12 by 2, showing the resiliency of its walls and is provided with a pin 13 which holds the valve of the stem open permitting escape of the air in the tube through passages 14 in the cap. During the transfer of the tube from the inspecting or testing station to the deating means a substantial amount of the enclosed air is expelled. The pressure, however, is not suiilcient to completely expel the air from the tube and this is accomplished by the application of a Vacuum. My improved mechanism for this latter step comprises a, deilatlng head 15, a number of which may be connected as by Ts 16 to a vacuum line 1'7. 'I'he head 15 is provided with a valve 19 which, when the valve parts are shown in the position of Fig. 3, open the vacuum to nozzle 20 projecting from the head 15. The free end of nozzle 20 is of a diameter substantially the same, or slightly smaller, than the normal diameter of the inilating cap 10 carried by the valve stem 11 so that when the end of the valve stem is forced into nozzle 20 the resilient Walls of the cap, particularly the shoulder 18, formed by straining the cap over the end of the stem, forms a seal between the valve stem and the nozzle. The lower wall of the nozzle is extended as at 21 to form a support which engages the valve stem to support the tube in deflating position. The extension 21 is preferably bent slightly upward as indicated at 22 to hold the valve stem in line with the axis of the nozzle 20 and the outer end of the extension is also preferably curved downward as at 23 to accommodate angle or bent types of valve stems. It will be apparent that the downwardly bent portion 23 does not interfere with the use of the device for straight valves. With the valve stem of the tube to be deflated positioned as above described and as shown in dotted lines in Fig. 2, valve 19 is opened as shown in Fig. 3 and the air completely removed from the tube by the Vacuum. In normal operation one operator handles a plurality of deating heads and it may happen that when he comes to remove the tube from a head the application of the vacuum has been suicient to not only withdraw the air from the tube but to wrinkle or otherwise deform it due to the creation of a partial vacuum in the tube itself. To correct this condition, and to break the vacuum so that valve stem and cap may be easily removed, the valve 19 is turned to the position shown in Fig. 4 to cut off the vacuum and vent the nozzle and tube to the atmosphere through a small aperture 25 in the head 15, permitting suiiicient air to enter the tube to allow the tube to return to normal deated condition.

Where high Vacuum is used or the deating cap does not make a sufliciently tight fit in the end of nozzle 20 the cap 10 may be drawn from the end of the stem 11 into the nozzle 20 and to prevent this I provide a transverse pin 26 adjacent the end of the nozzle which prevents passage of the deilating cap too far into the nozzle.

Having thus described my invention. I claim:

In a vacuum device for deilating pneumatic tubes having valved stems, wherein the stem of on the valve stem of the tube to be deflated When the capped end of the stem is forcibly telescoped into the nozzle, andvalve mechanism in the head operable in one position to supply vacuum to the nozzle to evacuate the tube and in a second position to permit atmospheric pressure to enter the tube.

WALTER V. SMITH. 

